1. Field of the Invention
This invention relates to upstream and downstream passage of migratory fish, and more particularly to the determination of the efficacy of dam bypass methods and apparatus.
2. Related Art
As briefly reviewed hereinafter, there is considerable prior art addressing methods and apparatus to facilitate and enhance the passage of migratory fish past manmade waterway barriers, i.e. dams. What has been lacking heretofore are methods and apparatus to adequately test, evaluate and compare the performance of such fish passage systems under known and controlled conditions. The invention disclosed herein fills this long standing need.
Many methods for improving the passage of fish past man-made barriers have been proposed and are in use. Two common methods include fish ladders and barging the fish from one side of a dam to the other. Other systems include Zimmerman (U.S. Pat. No. 4,629,361) who discloses an integrated bypass fishway comprised of tubes which enable fish to swim on a near natural level with the original streambed without ladders, locks, etc. Zimmerman includes devices which attempt to mimic some of the natural aspects of the original stream.
I have invented a method and apparatus for the passage of fish to the sea (U.S. Pat. No. 5,161,913) which includes the creation of water flow within a main conduit and in one or more collection tubes flowing into the main conduit from spawning areas. Lighting within the conduit is provided to attract and guide the fish toward the downstream side of a dam. The fish are preferably siphoned over the dam.
Eikrem et al. (U.S. Pat. No. 6,273,639) teaches a more complex conduit fish bypass passage system that involves a plurality of valves and valve actuators disposed in series within the conduit. The valves form chambers in the conduit which upon their selective opening and closing urge the fish through the conduit.
With varying degrees of success, many other methods and devices have been conceived and put into use that are designed to allow the free passage of migratory fish past waterway barriers. However, the art is silent with respect to methods and equipment that are suitable for a comparative evaluation of such fish bypass systems under controlled and identical conditions.
Thus it is an object of the present invention to provide methods and apparatus that permit the comparative evaluation of waterway barrier fish bypass systems. It is a further object of this invention to provide such an apparatus and methods that permit the simultaneous evaluation under similar environmental conditions of the multiple bypass systems undergoing evaluation. It is still another object of this invention to provide such apparatus and methods that provide a quantitative determination of each test system""s effectiveness. It is yet another object of this invention to provide a system that is safe to its operators, the migratory fish and the environment. It is a final object of this invention to provide an evaluation system that is inexpensive to fabricate and operate.
This invention of a fish test circuit for the evaluation of waterway barrier bypass systems preferably comprises a closed loop conduit having at least one bypass system test station, a means for providing water flow within the conduit, a means for introducing fish into the conduit, and a means for measuring the effectiveness of the bypass system(s) under test. In the preferred embodiment of this invention, the means for measuring the effectiveness of the bypass system(s) under test includes a means for determining the survival or mortality rate of the fish as they pass through each bypass system undergoing test. An important feature and benefit of this invention is the capability to evaluate multiple and differing bypass systems under similar water flow, water condition and water quality conditions.
In addition, the fish test circuit of this invention may also include known means for controlling the environmental conditions and quality of the water within the conduit. Alternative embodiments of this invention may also include known methods and apparatus for illuminating conduit sections and viewing the fish within the conduit.
These and many other features and attendant advantages of the invention will become apparent as the invention becomes better understood by reference to the following detailed descriptions and accompanying drawings.